*{
    margin: 0;
    padding: 0;
    list-style: none;
    text-decoration: none;
}
img{
    display: block;
    width: 170px;
    height: 100%;
}
header{
    display: flex;
    background: linear-gradient(to bottom,#f4f5f9 60%,#e2e2e2);
    .logo{
        height: 70px;
        margin: 0 50px 0 60px;
    }
}
nav{
    ul{
        display: flex;
        height: 70px;
        li{
            border: 0px solid#000;
            border-right-width: 1px;
            border-image: linear-gradient(#fff,rgba(0,0,0,0.2))1;
            position: relative;
            a{
                height: 70px;
                line-height: 70px;
                display: block;
                width: 150px;
                text-align: center;
                color: #000;
            }
                }
            }
        }
        nav>ul>li:last-child{
            border: none;
        }
        nav>ul>li:hover .drowmenu{
            display: block;
        }
        ul li:hover{
            background: rgb(219,219,219);
        }
.drowmenu{
        position: absolute;
        display: none;
        ul{
            display: flex;
            flex-direction: column;
            li{
                border: none;
                background: linear-gradient(to bottom,#f4f5f9 60%,#e2e2e2);
            }
        }
}
picture{
    width: 1500px;
    height: 518px;
    display: contents;
}